Engage in the thought experiment that you are/were/will be every human for a sec. Is self-harm morally ok? Many would say yes. So "the egg" already gives those people a pass to hurt everyone else in this world because it's a form of self-harm. Great. Now for those who explicitly don't want to self-harm. "The egg" implies that your rebirths happen serially in meta-time. You live this life, then the next, then another,... those lives may overlap on earth, but in egg-time, they don't. This means you can statistically expect you've already lived 50% of them. There's no guarantee of this, but the distribution is normal, not uniform [1] (similar reasoning found in doomsday argument [2]). 50%, give or take, humans out there you've already been. Everything you do to them, you do to your PAST self. You're not only absolved of moral accountability, but also of the physical consequences of treating them horribly. So while "the egg" tries to do the opposite, it really seems to justify psycho maxxing.

[1] https://en.wikipedia.org/wiki/Central_limit_theorem

[2] https://en.wikipedia.org/wiki/Doomsday_argument